Tool and method for use in assembling a stator assembly of an electric machine

ABSTRACT

An end cap for use with a stator assembly is provided. The end cap includes a tooth portion, a yoke portion, and a lip. The tooth portion includes a first end and an opposite second end and the yoke portion is formed at the first end of the tooth portion. The yoke portion includes at least one arm that extends from the tooth portion. The lip is defined along at least one of the tooth portion and the at least one arm portion.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a divisional application and claims priority to U.S.patent application Ser. No. 13/569,038 filed Aug. 7, 2012, which claimspriority to U.S. Provisional Application No. 61/624,051 filed Apr. 13,2012, which are both hereby incorporated by reference in its entirety.

BACKGROUND OF THE INVENTION

The embodiments described herein relate generally to an electric machineand, more particularly, to a stator assembly included within theelectric machine that includes an end cap for insulating statorlaminations.

In at least some known salient-pole-type electrical machines, a statorcore is formed from stator laminations. Magnet wire is wound aroundportions of the stator core to form a stator winding. End caps may beused to insulate end turns of the magnet wire from an electric ground.At least some known stator laminations are formed by punching a linearstrip of stator teeth from a sheet of stock material. The statorlaminations are stacked to form the stator core, which includes aplurality of stator segments. The end caps are positioned such thatmagnet wire may be wound about the stator segments. The end caps areconfigured to provide electrical insulation between the statorlaminations and the magnet wire winding.

In at least one known stator assembly, the stator core includes openingsconfigured to receive features included in the end cap. The features areused to secure the end caps to the stator core such that the end capsare properly aligned with stator core teeth. However, the openings inthe stator core cause undesirable electromagnetic characteristics.

In at least another known stator assembly, each end cap includes a postor hook that protrudes away from the end cap. A tie-down winds betweenadjacent stator segments and engages with the hooks of adjacent end capsto hold the adjacent stator segments together during assembly. However,using a tie-down to engage posts of adjacent stator segments does notinsulate the stator core from the magnet wire.

BRIEF DESCRIPTION OF THE INVENTION

In one aspect, a method of assembling a stator assembly is provided. Thestator assembly includes a plurality of stator segments, each statorsegment including at least a portion of a core and at least one end cap.The core includes a tooth having at least one end face and each end capincludes a yoke portion and a tooth portion. The stator assembly isassembled using a tool that includes a first member and a second memberextending therefrom. The method includes engaging the tool with the atleast one end cap, aligning the at least one end cap with the at leastone end face using the tool, and winding wire about the core tooth suchthat the at least one end cap is positioned between the at least one endface and the wire.

In another aspect, a tool for use in assembling a stator assembly of anelectrical machine is provided. The tool includes an elongated body, aplurality of first members extending from the elongated body, and aplurality of second members extending from the elongated body. Theplurality of first members and the plurality of second members arealigned with each other along a length of the elongated body such thatmember pairs, each including a first member and a second member, aredefined along the length of the elongated body.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of an exemplary stator assembly.

FIG. 2 is a perspective front view of the stator assembly shown in FIG.1.

FIG. 3 is a close-up perspective view of the stator assembly shown inFIG. 1.

FIG. 4 is a close-up front view of the stator assembly shown in FIG. 2.

FIG. 5 is perspective view of an exemplary end cap that may be includedin the stator assembly shown in FIG. 1.

FIG. 6 is a perspective view of a second side of the end cap shown inFIG. 5.

FIG. 7 is a perspective view of an exemplary insulation member that maybe included in the stator assembly shown in FIGS. 1-3.

FIG. 8 is a cross-sectional view of the stator assembly shown in FIG. 3taken at line 8-8.

FIG. 9 is a perspective view of an exemplary stator segment that may beincluded in the stator assembly shown in FIG. 1.

FIG. 10 is a perspective view of the stator assembly shown in FIG. 1 andan exemplary tool for use in assembling the stator assembly.

FIG. 11 is a perspective view of the tool shown in FIG. 9.

FIG. 12 is a cross-sectional view of the stator assembly shown in FIG.10 taken at line 12-12.

DETAILED DESCRIPTION OF THE INVENTION

The methods and systems described herein relate generally to a statorassembly included within an electric machine. More specifically, thestator assembly includes an end cap that facilitates reducing electricalconductive transfer between a stator winding and a stator core.Furthermore, the end caps include a lip feature formed therein that isconfigured to engage a corresponding insulation member such that eachend cap is held in a desired positioned against respective statorlaminations until wire has been wound about the stator segment.

More specifically, each end cap includes lip features that areconfigured to engage corresponding cuffs of an insulation member. Thelip features allow the cuffs to latch onto the end cap, thereby allowingthe cuffs to hold the end cap in a desired position. Moreover, wirewound about the core laminations may lead to mechanical stress inducedupon the end caps and the insulation member. More specifically, the wireapplies the greatest amount of mechanical stress at the corners of thestator laminations. In some embodiments, to provide additional strength,the cuffed features are located adjacent to areas of the statorlaminations that are subject to the greatest mechanical stress. Inaddition, the lip features facilitate maintaining the insulation memberin place adjacent to a stator segment. As such, both the end cap and theinsulation member remain stationary as wire is wound about each statorsegment.

In the exemplary embodiment, the end caps are constructed of anon-conductive material that has sufficient strength to withstand theforces required to wind the wire about the stator segments whilemaintaining electrical clearances. In the exemplary embodiment, the endcaps are not overmolded and do not significantly reduce the slot areabetween adjacent stator segments. As such, the amount of copper wirethat may fit into the slot area is not significantly reduced by the endcaps.

As described in more detail below, the end caps have a substantiallyrounded shape such that wire may be more easily wound about each statorsegment. Generally, known end caps have sharp corners that require agreater force to be applied to wind wire against the end caps. Windingwire about corners of the end caps requires bending the wire into arectangular configuration. Furthermore, abrupt changes in curvature ofthe end caps lead to distortion of the wire such that a reducedcross-sectional area of wire winding forms a hot spot. As such, currentembodiments of the present invention facilitate reducing the forcerequired to wind wire about each stator segment when compared tonon-arcuate end caps.

FIG. 1 is a perspective view of an exemplary stator assembly 100. In theexemplary embodiment, stator assembly 100 is configured for use in, forexample, a brushless direct current motor, a permanent magnetalternating current (PMAC) motor, and/or any other suitable electricalmachine. In the exemplary embodiment, stator assembly 100 includes astator core 110, a plurality of end caps 300, and a plurality ofinsulation members 400. Stator assembly 100 may include a plurality ofstator segments 200, for example, a first stator segment 202, a secondstator segment 204, a third stator segment 206, a fourth stator segment208, a fifth stator segment 210, a sixth stator segment 212, a seventhstator segment 214, an eighth stator segment 216, a ninth stator segment218, a tenth stator segment 220, an eleventh stator segment 222, and atwelfth stator segment 224. Although illustrated as including twelvestator segments, stator assembly 100 may include any suitable number ofstator segments such that stator assembly 100 functions as describedherein.

In some embodiments, core 110 may be formed as a stack of flatlaminations (not shown) made of a highly magnetically permeablematerial, or core 110 may be a solid core. The plurality of laminationsthat form core 110 may be either interlocked or loose.

In some embodiments, the plurality of end caps 300 includes first endcaps 301, 303, 305, 307, 309, 311, 313, 315, 317, 319, 321, and 323, andsecond end caps 302, 304, 306, 308, 310, 312, 314, 316, 318, 320, 322,and 324. In the exemplary embodiment, each stator segment includes afirst end cap and a second end cap. For example, third stator segment206 includes first end cap 305 and second end cap 306, fourth statorsegment 208 includes first end cap 307 and second end cap 308, fifthstator segment 210 includes first end cap 309 and second end cap 310,and sixth stator segment 212 includes first end cap 311 and second endcap 312. Furthermore, in some embodiments, the plurality of insulationmembers 400 includes insulation members 402, 404, 406, 408, 410, 412,414, 416, 418, 420, and 422.

FIG. 2 is a perspective front view of stator assembly 100. In theexemplary embodiment, a plurality of slots are defined between adjacentstator segments 200. For example, a first slot 262 is defined betweenstator segments 202 and 204, a second slot 264 is defined between statorsegments 204 and 206, a third slot 266 is defined between statorsegments 206 and 208, a fourth slot 268 is defined between statorsegments 208 and 210, a fifth slot 270 is defined between statorsegments 210 and 212, a sixth slot 272 is defined between statorsegments 212 and 214, a seventh slot 274 is defined between statorsegments 214 and 216, an eighth slot 276 is defined between statorsegments 216 and 218, a ninth slot 278 is defined between statorsegments 218 and 220, a tenth slot 280 is defined between statorsegments 220 and 222, and an eleventh slot 282 is defined between statorsegments 222 and 224. Accordingly, as explained in more detail below, aninsulation member 400 may be positioned within each slot tosubstantially insulate core 110.

FIG. 3 is a close-up perspective view of stator assembly 100 and FIG. 4is a close-up front view of stator assembly 100. It should be understoodthat end caps 310 and 312 have been removed for illustrative purposesonly. In the exemplary embodiments, core 110 includes a plurality ofyokes 250, a plurality of feet 254, and a plurality of teeth 252extending therebetween. More specifically, for example, a portion ofcore 110 of fifth stator segment 210 includes a foot 240 having a firstportion 242 and a second portion 244 extending from tooth 252 of statorsegment 210, and a portion of core 110 of sixth stator segment 212includes a foot 241 having a first portion 243 and a second portion 245extending from tooth 252 of stator segment 212. In some embodiments, atleast one of the plurality of stator segments 200 includes athrough-bore 226 for receiving a through-bolt (not shown). In oneembodiment, every third stator segment (e.g. stator segments 204, 210,216, and 222) includes through-bore 226 defined within respective yokes250. Core 110 also includes a plurality of flexible portions 258 thatconnect adjacent yokes 250 and are configured to enable stator assembly100 to be arranged annularly.

Furthermore, in the exemplary embodiment, one of the plurality ofinsulation members 400 is positioned within the slots defined betweenadjacent stator segments 200. More specifically, insulation members 400are positioned between adjacent teeth 252 of core 110. In oneembodiment, insulation member 410 extends along core foot portion 244 ofstator segment 210, along core tooth 252 of stator segment 210, alongcore yoke 250 of stator segment 210, along core yoke 250 of statorsegment 212, along core tooth 252 of stator segment 212, and along corefoot portion 243 of stator segment 212. As such, insulation member 410spans slot 270 defined between stator segments 210 and 212.

In some embodiments, insulation members 400 are coupled to end caps 300.For example, in the exemplary embodiment, insulation member 406 iscoupled to first end caps 305 and 307, and to second end caps 306 and308 such that each end cap 300 is positioned between an end face 256 ofcore 110 and winding 230. As such, portions of insulation members 404and 406 and end caps 300 are positioned between tooth 252 and winding230 to substantially insulate core 110.

More specifically, and using stator segment 206 for example, end caps305 and 306 and insulation members 404 and 406 are configured tosubstantially cover exposed laminations of core 110 of stator segment206. In some embodiments, end caps 305 and 306 and insulation members404 and 406 are positioned adjacent to and insulate core tooth 252 fromwindings 230. In the exemplary embodiment, wire 232 is wound about coretooth 252 to form windings 230 such that end caps 305 and 306, a toothportion 434 (shown in FIG. 7) of insulation member 406, and a toothportion 444 (shown in FIG. 7) of insulation member 404 are positionedbetween core tooth 252 and wire 232. Accordingly, windings 230 extend atleast partially into slots 264 and 266 and end caps 305 and 306 areshaped such that they do not extend into slots 264 and 266. Furthermore,in some embodiments, windings 230 may be positioned between yoke 250 andfoot 254 of stator segment 206.

FIGS. 5 and 6 are perspective views of end cap 300. In the exemplaryembodiment, end cap 300 includes a tooth portion 330, a yoke portion 350formed at a first end 331 of tooth portion 330, and a foot portion 340formed at a second end 332 of tooth portion 330. Tooth portion may haveany suitable shape that enables stator assembly 100 to function asdescribed herein. For example, tooth portion 330 may have asubstantially cylindrical shape that defines a semi-cylindrical cavity356 formed therein. Furthermore, cavity 356 extends the length of toothportion 330 from first end 331 to second end 332. Yoke portion 350includes a first arm portion 352 that extends from tooth portion 330, asecond arm portion 354 that extends from tooth portion 330, and acentral portion 358 defined therebetween. In the exemplary embodiment,fastener aperture 360 is defined in central portion 358. Foot portion340 includes a central portion 342 that is substantially rectangular inshape and oriented substantially perpendicularly to tooth portion 330.Foot portion 340 also includes a first portion 344 extending from toothportion 330 and central portion 342, and a second portion 346 extendingfrom tooth portion 330 and central portion 342. First portion 344 has ashape that corresponds to a shape of core foot first portion 242 (shownin FIG. 3), and second portion 346 has a shape that corresponds to ashape of core foot second portion 244 (shown in FIG. 3).

In some embodiments, a first fastening feature is included within endcap 300. For example, in the exemplary embodiment, end cap 300 includesat least one lip 380 defined along at least one of tooth portion 330 andone or both of first portion 352 and second portion 354 of yoke portion350. In the exemplary embodiment, lip 380 extends at least partiallyalong a first side 333 of tooth portion 330 and a second side 335 oftooth portion 330, and at least partially along a first side 337 of yokeportion 350 and a second side 339 of yoke portion 350. In oneembodiment, lip 380 may extend along first and second portions 344 and346 of foot 340. In another embodiment, lip 380 may extend at leastpartially along any combination of first and second sides 333 and 335 oftooth portion 330, and first and second sides 337 and 339 of yokeportion 350. Furthermore, in the exemplary embodiment, end cap 300includes an indentation 382 defined within tooth portion 330 and armportions 352 and 354. Indentation 382 is located on the outer edges oftooth portion 330 and arm portions 352 and 354 such that lip 380 isdefined by indentation 382. Furthermore, as mentioned above, lip 380 ofend caps 300 are configured such that they do not extend into and/orreduce the area of slots 262, 264, 266, 268, 270, 272, 274, 276, 278,280, and 282.

End cap 300 may be constructed from any suitable material that enablesend cap 300 to function as described herein. More specifically, end cap300 may be constructed of any suitable non-conductive material. Forexample, end cap 300 may be constructed of, but is not limited to,Valox® DR51M (“Valox” is a registered trademark of Sabic InnovativePlastics of Bergen op Zoom, Netherlands).

FIG. 7 is a perspective view of insulation member 400 that, in oneembodiment, is be included with stator assembly 100 (shown in FIG. 1).Each insulation member 400 of stator assembly 100 is substantially thesame and, as such, one insulation member 400 is described in detailherein.

Insulation member 400 may be formed from any suitable electricallyinsulated film or sheet material that enables insulation member 400 tofunction as described herein. For example, in some embodiments,insulation member 400 may be formed from a sheet of 1/1000^(th)inch-thickness paper, a thermoplastic material, a thermoset materials, aDacron/Mylar/Dacron (DMD) material, and TufQUIN® having a thickness ofat least 0.002 inch. In the exemplary embodiment, insulation member 400is formed from a sheet of Mylar® polyester film (“Mylar” is a registeredtrademark of E. I. du Pont de Nemours and Company of Wilmington, Del.)and is substantially symmetrical with respect to a vertical plane A(shown in FIG. 3). In some embodiments, insulation member 400 formedfrom a sheet of Mylar® polyester film has a thickness of 0.005 inch toabout 0.01 inch.

In the exemplary embodiment, insulation member 400 includes, incontinuous series, a first foot portion 432, a first tooth portion 434,a first yoke portion 436, a connection portion 440, a second yokeportion 442, a second tooth portion 444, and a second foot portion 446.A first bend 433 is defined between first foot portion 432 and firsttooth portion 434, a second bend 435 is defined between first toothportion 434 and first yoke portion 436, a third bend 437 is definedbetween first yoke portion 436 and connection portion 440, a fourth bend438 is defined within connection portion 440, a fifth bend 439 isdefined between connection portion 440 and second yoke portion 442, asixth bend 443 is defined between second yoke portion 442 and secondtooth portion 444, and a seventh bend 445 is defined between secondtooth portion 444 and second foot portion 446. Alternatively, insulationmember 400 has any suitable shape that corresponds to the shape of slots262, 264, 266, 268, 270, 272, 274, 276, 278, 280, and 282. Furthermore,alternatively, insulation members 401 and 423 (shown in FIG. 1) at theends of stator assembly 100 are each a truncated insulation member 401and 423, such as half of an insulation member 400.

Insulation member 400 is configured to substantially insulate core 110of each stator segment 200 from winding 230. More specifically, toothportions 434 and 444, yoke portions 436 and 442, and foot portions 432and 446 are configured to insulate core 110 from winding 230. Althoughstator segment 212 will be described in more detail below, the followingdescription may apply to any one of stator segments 200. In theexemplary embodiment, foot portion 432, tooth portion 434, and yokeportion 436 of insulation member 412 substantially cover surface 267 ofstator segment 212, and foot portion 446, tooth portion 444, and yokeportion 442 of insulation member 410 substantially covers surface 265 ofstator segment 212. In some embodiments, foot portion 432 of insulationmember 412 extends past second portion 245 of foot 241 into slot 268,and foot portion 446 of insulation member 410 extends past first portion243 of foot 241 into slot 266 to substantially insulate first and secondportions 243 and 245 of foot 241. Foot portions 432 and 446 may thenbend around first and second portions 243 and 245 of foot 241.

Connection portion 440 of insulation member 400 is configured to enablestator assembly 100 to be arranged in a substantially linear orientationand subsequently formed into an annular arrangement to a form a statorring. Connection portion 440 facilitates forming stator assembly 100into a stator ring by providing additional insulation material thatflexes as the plurality of stator segments 200 are bent into the annulararrangement. More specifically, connection portion 440 includes an angleθ₁ (shown in FIG. 3) that is from about 15° to about 45° when statorassembly 100 is arranged linearly. When stator assembly 100 is bent intothe annular arrangement to form the stator ring, fourth bend 438 flexessuch that θ₁ becomes a more acute angle. For example, when statorassembly 100 is arranged annularly, angle θ₁ is approximately 0°. Insome embodiments, angle θ₁ is dependent on the number of stator segments200 in stator assembly 100. For example, angle θ₁ is greater in a statorassembly including fewer stator segments, and angle θ₁ is smaller in astator assembly including more stator segments 200. The difference inangle θ₁ is dependent on the degree in which connection portion 440 mustbend when stator assembly 100 is arranged annularly to form a statorring.

Insulation member 400 also includes a second fastening featureconfigured to engage the first fastening feature of end cap 300. In theexemplary embodiment, insulation member 400 includes a body 450 having afirst end 451 and a second end 452. The second fastening featureincludes a first flap 462 extending from first end 451 of body 450 and asecond flap 472 extending from second end 452 of body 450. First flap462 is configured to form a first cuff 460 at first end 451, and secondflap 472 is configured to form a second cuff 470 at second end 452. Inthe exemplary embodiment, cuffs 460 and 470 extend along tooth portion434, yoke portion 436, connection portion 440, yoke portion 442, andtooth portion 444. In an alternative embodiment, cuffs 460 and 470 mayextend along foot portions 432 and 446 such that cuffs 460 and 470engage with lip 380 that extends along first and second portions 344 and348 of foot 340. Flaps 462 and 472 and cuffs 460 and 470 aresubstantially similar and, as such, first flap 462 and first cuff 460are described in more detail below. However, it should be understoodthat such a description may also apply to second flap 472 and secondcuff 470.

FIG. 8 is a cross-sectional view of fourth stator segment 208 taken atline 8-8. In the exemplary embodiment cuff 460 includes flap 462 thatextends from first end 451 and is folded over body 450. As such, acrease 468 is formed between flap 462 and body 450 at first end 451.Crease 468 may be oriented such that flap 462 is positioned a distancefrom body 450, or flap 462 may be oriented such that an end 466 of flap462 contacts body 450. In the exemplary embodiment, cuff 460 is notformed along foot portions 432 and 446. In an alternative embodiment,flap 462 extends along body 450 at any suitable portions of insulationmember 400. Furthermore, in the exemplary embodiment, when flap 462 isfolded over body 450, flap 462 extends along at least a portion of thelength of body 450, the length being between first end 451 and secondend 452.

Furthermore, in the exemplary embodiment, end caps 307 and 308 arepositioned adjacent to each end face 256 of core 110 such that cavity356 is defined between an inner surface 370 of each end cap 307 and 308and each end face 256. First cuff 460 couples to lip 380 of first endcap 308 to secure insulation members 406 and 408 to end cap 308 and endface 256. More specifically, end 466 of flap 462 contacts lip 380. Cuff460 can flex at bend 464 to increase a distance between end 466 and body450 to facilitate coupling insulation member 400 to end cap 308 and/orto tooth 252 (shown in FIG. 4). When coupled to end caps 307 and 308and/or tooth 252, cuffs 460 and 470 secure insulation members 400 inplace as wire 232 is wound about core tooth 252 to form winding 230(shown in FIG. 4).

FIG. 9 is a perspective view of an exemplary stator segment 200. In theexemplary embodiment, stator segment 200 includes lead wires 502 and atie member 504. Lead wires 502 extend along the length of statorassembly 100 (shown in FIG. 1) and tie member 504 is used to secure leadwires 502 to end cap 300. For example, in some embodiments, tie member504 circumscribes end cap 300 and is tightened to secure lead wires 502to end cap 300 and/or winding 230. More specifically, tie member 504engages with fastener aperture 320 of central portion 358 and a notch348 of foot portion 340 when tie member 504 circumscribes end cap 300.In the exemplary embodiment, tie member 504 is a zip-tie, but tie member504 may be any suitable component for securing lead wires 502 to end cap300 and/or winding 230. Moreover, in the exemplary embodiment, fasteneraperture 360 and notch 348 are sized such that tie member 504 is fixedlycoupled to end cap 300. Fastener aperture 360 is also shaped to receivea through-bolt (not shown).

FIGS. 10-12 are exemplary embodiments of stator assembly 100 assembledwith tools 500. In the exemplary embodiment, a first tool 506 isinserted into first end caps 301, 303, 305, 307, 309, 311, 313, 315,317, 319, 321, and 323 and a second tool 508 is inserted into second endcaps 302, 304, 306, 208, 310, 312, 314, 316, 318, 320, 322, and 324,.First and second tools 506 and 508 align the plurality of end caps 300with each end face 256 of core 110. Tools 500 include a plurality offirst members 512 and a plurality of second members 514 that each extendfrom a body 516 of first and second tools 506 and 508. Furthermore, inthe exemplary embodiment, first members 512 and second members 514 arealigned with each other and are equally spaced along the length of body516 such that each member 512 and 514 aligns with each end face 256.

Tools 500 align each respective end cap 300 to be positioned adjacenteach respective end face 256 by inserting first member 512 into cavity356. First member 512 is configured to have a shape corresponding to theshape of cavity 356. For example, in the exemplary embodiment, toothportion 330 has a substantially round shape and cavity 356 has asemi-circular cross-sectional shape. As such, first member 512 has asemi-circular cross-sectional shape. Moreover, in the exemplaryembodiment cavity 356 is sized to receive a portion of tie member 504and first member 512.

FIG. 12 is a cross-sectional view of stator segment 224. In theexemplary embodiment, tool 508 is inserted into end cap 324 by insertingfirst member 512 into cavity 356 adjacent inner surface 370 of toothportion 330. Second member 514 is coupled to end cap 324 and ispositioned on an opposite side of tooth portion 330. As such, secondmember 514 holds end cap 324 in place while wire 232 is wound about eachtooth assembly 236. Once winding 230 is in place, tools 510 are removedand stator assembly 100 is arranged annularly to form a stator ring.

The end cap described herein facilitates insulating a stator core fromelectrical conductivity and has a rounded shape to decrease the amountof force required to wind wire about each stator segment. Thesubstantially rounded shape of the end cap results in a cavity beingformed between the end cap and the stator core. The cavity receives afirst member of a tool that is used to align each end cap with the eachcore end face. As such, wire may be wound about each stator segmentwithout having to individually align each end cap. Furthermore, the endcap described herein includes a lip feature that may be used incombination with a cuff of an insulation member to press the end capagainst each end face. As such, the end cap remains stationary tofacilitate assembling the stator assembly.

This written description uses examples to disclose the invention,including the best mode, and also to enable any person skilled in theart to practice the invention, including making and using any devices orsystems and performing any incorporated methods. The patentable scope ofthe invention is defined by the claims, and may include other examplesthat occur to those skilled in the art. Such other examples are intendedto be within the scope of the claims if they have structural elementsthat do not differ from the literal language of the claims, or if theyinclude equivalent structural elements with insubstantial differencesfrom the literal languages of the claims.

1-14. (canceled)
 15. A method of assembling a stator assembly includinga plurality of stator segments, each stator segment including at least aportion of a core and at least one end cap, wherein the core includes atooth having at least one end face, each end cap including a yokeportion and a tooth portion, the stator assembly assembled using a toolincluding a first member and a second member extending therefrom, saidmethod comprising: engaging the tool with the at least one end cap;aligning the at least one end cap with the at least one end face usingthe tool; and winding wire about the core tooth such that the at leastone end cap is positioned between the at least one end face and thewire.
 16. The method in accordance with claim 15, wherein the at leastone end cap is contoured to define a cavity therein, wherein engagingthe tool with the at least one end cap further comprises translating thetool relative to the at least one end cap such that the first member isinserted into the cavity and such that the second member is coupled tothe at least one end cap, wherein at least a portion of the at least oneend cap is positioned between the first member and the second member.17. The method in accordance with claim 16, wherein translating the toolfurther comprises inserting the first member having a shapecorresponding to a shape of the cavity.
 18. The method in accordancewith claim 15, wherein the stator assembly includes a plurality of teethand a plurality of end caps, wherein aligning the at least one end capfurther comprises aligning the plurality of end caps with eachrespective end face of the plurality of teeth with a plurality of firstmembers and a plurality of second members spaced along a length of thetool.
 19. The method in accordance with claim 15 further comprisingsecuring a lead wire to at least one of the wire and the at least oneend cap.
 20. The method in accordance with claim 15 further comprising:removing the tool from the at least one end cap; and arranging theplurality of stator segments annularly to form a stator ring.
 21. Themethod in accordance with claim 18 further comprising translating thetool relative to the plurality of end caps such that the plurality offirst members and the plurality of second members are engaged with theplurality of end caps simultaneously.
 22. A tool for use in assembling astator assembly of an electrical machine, said tool comprising: anelongated body; a plurality of first members extending from saidelongated body; and a plurality of second members extending from saidelongated body, wherein said plurality of first members and saidplurality of second members are aligned with each other along a lengthof said elongated body such that member pairs, each including a firstmember and a second member, are defined along the length of saidelongated body.
 23. The tool in accordance with claim 22, wherein saidplurality of first members and said plurality of second members areoriented parallel relative to each other.
 24. The tool in accordancewith claim 22, wherein said plurality of first members and saidplurality of second members are both equally spaced along the length ofsaid elongated body.
 25. The tool in accordance with claim 22, whereinsaid plurality of first members and said plurality of second members areoriented perpendicularly relative to the length of said elongated body.26. The tool in accordance with claim 22, wherein said plurality offirst members have a semi-circular cross-sectional shape.
 27. The toolin accordance with claim 22, wherein said plurality of first membersextend a greater distance from said elongated body than said pluralityof second members.
 28. The tool in accordance with claim 22, wherein agap is defined between said first member and said second member in eachmember pair.